Carbohydrates Overview

Carbohydrates

• Carbohydrates are a group of macromolecules, made up of carbon, hydrogen, and oxygen.
• They act as a primary source of energy.
• Monosaccharides are simple sugars, like glucose, fructose, and galactose.
• Disaccharides are formed when two monosaccharides join through a condensation reaction, releasing a water molecule. Examples include sucrose, lactose, and maltose.
• Polysaccharides are complex carbohydrates formed by joining many monosaccharides. Starch, glycogen, and cellulose are examples.
• Starch is a storage polysaccharide found in plants. It is composed of amylose (linear structure) and amylopectin (branched structure), and is insoluble in water.
• Glycogen is a storage polysaccharide found in animals. It's highly branched.
• Cellulose is a structural polysaccharide found in plant cell walls. It's composed of unbranched chains of glucose.
• Condensation reaction- bonds two molecules with the loss of water.
• Hydrolysis happens when water is added to break the bonds between two molecules.

Starch

• Starch is used for energy storage in plants.
• It's a polysaccharide composed of amylose and amylopectin, both made from glucose.
• Starch is insoluble in water and stored in plant cells.

Glycogen

• Glycogen is a branched polysaccharide used for energy storage in animals.
• It's made of repeating glucose units.
• Glycogen is found primarily in the liver and muscles.

Cellulose

• Cellulose is a linear polysaccharide found in plant cell walls.
• It's composed entirely of glucose units.
• Cellulose is a strong, rigid material.

Monosaccharides & Polysaccharides

• Monosaccharides like glucose are used as a source of energy.
• Polysaccharides like starch and glycogen store energy for later use.

Disaccharides

• Sucrose (glucose + fructose): table sugar
• Lactose (glucose + galactose): found in milk
• Maltose (glucose + glucose): found in germinating seeds